In the conventional design of bicycle, the saddle post is clamped into a socket on the upper end of the main seat column of the bicycle frame. The saddle is adjustable as regards its height, in that the saddle clamp may be released, allowing the saddle to be raised and lowered in the socket.
As to its construction, the saddle clamp usually comprises a bolt which is mounted tangentially in the seat column, and a complementary nut. The nut may either be a simple hexagonal nut, which can only be turned by the use of a spanner or wrench, or the nut may include a handle, and be hand-manipulable.
When cycling long distances, and especially when touring over different types of terrain, the cyclist wishes to adjust the height of the saddle from time to time. The nut with a handle on is preferred to the hexagonal nut, which needs tools, in this case.
The problem with providing a saddle clamp which can be released without tools is that it is also easy for a thief to release the saddle clamp, and remove the saddle from the bicycle.
The invention provides a security device that renders the saddle easy to adjust but at the same time difficult to steal.
The security device of the invention also is inexpensive to construct; is not bulky, for ease of packaging and display; is easy to apply to the bicycle using only basic skills and tools; and provides an adequate deterrent against the casual thief.
It should be noted that a bicycle is not in any event a secure article. A determined thief, equipped with a reasonably comprehensive tool kit, is easily able to make off with most of the components of the bicycle, even if, for example, the frame of the bicycle is secured by a padlocked chain to a fixture. And a thief equipped with a chain cutter is not stopped by a padlocked chain.
It is recognized in the invention that it is effective to take security precautions against the casual thief, who is not equipped with tools, but that further security, aimed at the well-equipped, determined thief, is generally too expensive to be worthwhile.
However, in the case of the cycle touring enthusiast, not only is the trend now to replace the hexagonal saddle clamp-nut with a hand-manipulable nut, but the cyclist increasingly requires better protection against thieves.
A touring bicycle can be quite sophisticated, and some of the components, such as the saddle, can be expensive items, and therefore attractive to a thief.
It is recognized that a security device for a saddle therefore should be such as to repel a thief equipped with a spanner or wrench, as well as the thief equipped with no tools at all, but that it is hardly worth making the device proof against a thief equipped with a chain cutter or a saw.
A security device for a saddle should not interfere with the adjustment of the saddle, should be neat and unobtrusive in appearance, and should be inexpensive to manufacture, and should be easy and safe to install.